Strawberry is one of the most popularly consumed berries in the world. These berries are easy to find all year, but they’re at their best during the spring (and summer) months. These juicy red orbs are a joy of summer fruit eating. So, there’s nothing more disappointing than going to eat your freshly picked, sweet strawberries only to discover that the ones on the bottom of the punnet are already mushy and moldy.
To increase the berries’ shelf life, researchers at Thammasat University and Chulabhorn Research Institute in Thailand have developed an invisible, edible coating made with cannabidiol (CBD) that extends the freshness of strawberries.
CBD has been shown to have antioxidant and antibacterial effects. Previous studies found that CBD limited the growth of some bacteria and pathogenic fungi, such as the ones that cause fresh fruits and vegetables to rot.
Now, researchers combined CBD with a biodegradable polymer already used in drug delivery to produce 400-nm-wide particles. They then mixed the most stable nanoparticles, containing 20% by weight CBD, with water and a food additive called sodium alginate. Strawberries were then dipped into the resulting solutions containing different amounts of nanoparticles before a second dip into a mixture of ascorbic acid and calcium chloride, which turned the colorless coating into a gel.
In order to test the coating’s preservative abilities, researchers placed the untreated and treated strawberries in open plastic containers at refrigerator temperatures. After 15 days, they found that CBD-treated berries ripened and decayed much more slowly than untreated ones.
The edible coating preserved the berries’ dark red appearance, enhanced their antioxidant activity the most, and exhibited the largest antimicrobial protection over the storage period, suggesting that this version would lead to the longest shelf life.
With further studies, new CBD coating could be used to create a colorless antimicrobial coating for active food packaging.
- Pongpat Sukhavattanakul, Thanyaluck Thanyacharoen, Piyachat Chuysinuan, Supanna Techasakul, and Sarute Ummartyotin. Influence of a Transparent and Edible Coating of Encapsulated Cannabidiol Nanoparticles on the Quality and Shelf Life of Strawberries. ACS Applied Materials & Interfaces, 2023; DOI: 10.1021/acsami.3c04036